


Prillya's Bumpy Ride

by Gothdresser



Category: Fate/kaleid liner PRISMA ILLYA
Genre: Accidents, Diapers, Driving, Futanari, Gen, Panty Poop, Pee, Piss, Scat, Shemale, Soiling, Wetting, cum, messing, peeing, poop
Language: English
Status: Completed
Published: 2019-07-22
Updated: 2019-07-22
Packaged: 2020-07-10 17:47:05
Rating: Mature
Warnings: Underage
Chapters: 1
Words: 3,159
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/19909714
Author URL: https://archiveofourown.org/users/Gothdresser/pseuds/Gothdresser
Summary: If there's one thing to take from Irisviel's driving in Fate/Zero and Illya's driving in Fate/Hollow Ataraxia, it's that the Einzbern family has incredible driving skills!Oh, who am I kidding... Irisviel is a very scary driver~ But it's just a simple ride to school though, it can't be too bad, right? Right...?Done for the Prillya girls' shared birthday (7/20), even if just a smidge late~





	Prillya's Bumpy Ride

“Oh! Illyaaaa, today Mama will be driving you girls to school~” Illya’s blood ran cold as those words were said, her backpack hitting the floor as her shaking hand couldn’t hold it any longer. She could feel her legs quivering at just the suggestion, one hand zooming to her crotch.

“Um, Illya, are you okay?” Putting a hand on her friend’s shoulder, Miyu cocked her head while using Illya for support to shoehorn her second shoe on. She was ready for school and Illya’s mom was kind enough to drive them, but it seemed like that was the opposite of what she wanted.

“U-uh, just give me a moment…” Slipping away from her friend, Illya impatiently called, “S-S-Seellaaaaaaa!” as she headed upstairs, taking a sharp corner around the railing and bumping right into her.

All her freshly folded laundry clattered to the ground, the maid not knowing whether to try to save the clothes or steady her young mistress’s agitated self. “I-Illya, will you please calm down, and tell me what’s the matter.” Bending down to pick up the laundry, it was tough for her to imagine that something could alarm the young girl so much.

Wiggling in place while attempting to follow Sella’s direction, Illya kept glancing towards down the stairs, caught in the need of hurrying up before she had to leave. “I can’t wear my panties to school today. I-I think I need a d-... diaper…” Blushing a little, it was hard to admit the necessity of it, but desperate times called for desperate measures. Especially since she didn’t want to be desperately trying to not ruin the seats of Mama’s car.

Folding the clothes neatly back into the basket, she wasn’t surprised by Illya’s tendency to blow simple problems out of proportion. Not the only thing the little girl liked to blow out as Sella was all too familiar with, having bagged and tossed quite the heavy diaper in the trash already today, not unlike most mornings. “And why would you ever need to wear a diaper to school, Young Mistress? I already cleaned you up once today and I hopefully won’t have to do so again when you arrive home from school.” 

Hands resting on her hips, she was already used to cleaning up so many sullied panties with two little girls around the house, not to mention when Leysritt was too lazy to even move an inch towards the restroom. It was almost like no one in the house was potty-trained besides her and maybe Mistress Irisviel, but she knew too well how terribly tough it was to clean soiled tights. There was no reasonable argument for a young girl of the Einzbern family to be wearing a diaper to school when she was already in the fifth grade.

“Mama wants to drive us to school…” However, upon hearing just those words, Sella was quick to understand as her hands darted to her own crotch, her panties dampening a little from just the thought of Mistress Iri’s driving. Almost immediately after the maid unclenched and felt safe enough not to have an accident, Illya felt her hand taken by Sella and pulled towards her room to prevent another incident like what happened at the beach. Even though Illya had already mentioned her need, just a smidge of awkwardness hung in the air as Illya laid back on her bed. “S-Sella, can you bring me a diaper, please? And uh, maybe get one for Miyu and Chloe as well.”

“Of course, young mistress~” Heading into the closet and pulling out a plastic package from among the other night-time supplies, Sella returned with three small childish diapers, characters of a magical girl show adorning the front. “It’ll be just a moment.” Setting two diapers to the side, Illya’s panties were removed and tossed to the laundry bin, her immature little girl cock now concealed by the thickness of the padding. Illya had to fan away a small puff of the baby powder as the tapes were stretched around her petite waist, her crotch swaddled in the safety of the bulky underwear.

A couple of checks around the leg guards and a pat on the front of her diaper signaled the end of the change, and Illya wiggled her padded butt off the bed and adjusted the front of her skirt. “Thank you, Sella, I’ll help the others with their changes~” Scooping up the pair of diapers, Illya hurried out of her room too fast to be stopped by Sella for any potential problems. 

The house was still pretty quiet though since it was early in the morning, the main noise attracting Illya being the tanned girl emerging from her own room in nothing but a heavily soiled diaper under an almost see-through nightie. “Caught you just in time, make sure to put this on since Mama is driving again.” Pulling one diaper out to present to Chloe, her twin held off from taking the thick diaper with youthful designs.

A smile instantly bloomed on Chloe’s face as she heard the news. “Really? And miss out on all the fun Mama has when playing with her toy? No-ope~” She brushed aside the outstretched offer and moved past Illya towards the bathroom, her school clothes draped over her arm. “I’ll be down pretty soon after I clean up and get dressed! Make sure to watch out for what happens to your padded butt though~” The door shut and locked between them, leaving Illya still holding two diapers along with some giggling coming from the closed room.

At least Miyu would be smart enough to realize the danger of the situation, but a thought struck Illya: Miyu hadn’t had the luxury to ride with Mama yet. She was still wise though, and that’s what Illya had to rely on as she headed downstairs, the door already open. “Oh, Chloe is still getting ready, so I think we should have enough time to get you changed. Mama’s driving is… well, I think it’s better to be safe than sorry…”

Having the folded item thrust into her arms, Miyu looked it over and unfolded it with a small crinkling, examining the designs and cushiness when she realized what it was. The diaper fell right to the floor with a light rustle while the young girl took a step away from it. “I-Illya? Why exactly do you want me to wear something so… so… infantile?” Miyu had her occasional problem at night for both ends, but Luvia made sure she had pull-ups prepared, and a diaper during the day was something she never expected to be suggested to wear. Illya had her eccentricities, but there it was hard to justify wearing baby diapers to school.

That reaction was exactly what Illya hoped to avoid, picking up the discarded padding and folding it back up again. “It’s hard to explain, but I don’t want you to learn why after you experience Mama’s driving.” The reason for a diaper was obvious to herself, but the thought of trying to explain precisely what would happen was something that was quite embarrassing, as well as making Illya stir at the crotch. Perversion wasn’t her original intent, although the thought of seeing Miyu’s padded butt helped to make her want to tape up the proper protection around it. “Please just trust me, Mama was taught to drive in an… interesting way and I think you’d really prefer the diaper.”

“It’s just a ride to school, I’ll be fine without one. If you’re so insistent, why not wear one yourself or get Chloe to join you?”

Illya’s heart sank as her lack of a clear argument was hurting her, Miyu pointing out two important things though about the situation. “Well, Chloe didn’t want to wear one, and as for me… there’s a reason why I only have two with me.” The red of her face was greatly contrasted by her albino complexion, using the spare diapers to cover part of her face. There were implications to be drawn about why she would be wearing a diaper, specifically about its usage that she couldn’t exactly tell if it went over Miyu’s head, but Illya was reminded by the crinkling of her nervous shuffle next to the side of the dark-haired girl.

“Only two? Well, it sounds like you might need to save both of them for yourself, but I’m not interested in wearing something so immature.” It really was only a ride to school, and yet Illya seemed to be overreacting to it so much. Her friend always acted in such an overexaggerated manner, so it didn’t phase Miyu to see her acting up once again. “Let’s just go to school already, I’m sure it will be fine.”

With Miyu heading out the door, Illya was shortly left alone to pack the diapers in her backpack, knowing she’d need at least one for herself later. She just hoped that Miyu would be okay enough after the ride, more than happy to help her out when she eventually needed it. That’d probably leave Chloe without a change, but something about how her doppelganger had reacted before worried her.

Speaking of the devil, her other self came rushing down the stairs, all dressed up for school and with a hop to her step. “Come on already, hurry up if you don’t want to be late for more than just the toilet~” Something definitely felt off about how Chloe was acting, as if she had some plan, but Illya followed her out anyway.

Even with Mama’s favorite car tucked away in the garage for when she went out with Papa, the three-pronged star shone in the morning sun as Illya passed the front of the car and got on the right side to join the other two. In a line in the backseat, Chloe was placed behind the driver’s seat with Miyu and then Illya to her side. As Illya looked over, the anticipation was vastly different between the three of them. Chloe’s excitement was visible as she fidgeted in her seat, as compared to Miyu who sat up properly with her backpack in her lap. Illya could feel herself gulping as the car slowly backed out of the driveway, a small wave to Sella who curtly nodded back to Illya as if sending her off to her fate.

Rolling down the street and up to the first stop sign, Illya felt tense as no one else in the car seemed ready for what was to happen. She was even so obvious about her nervousness that Miyu chimed in. “I-Illya, are you feeling sick? It’s not good to bring a cold to school and we’re still near your house if you want to turn back.”

“It’s fine, I’m just afraid of-” Cut off by the sound of screeching tires, the front of Illya’s diaper was instantly soaked as she was jolted back against the seat, one hand on the grab handle while the other gripped her seat. She barely had the time to be prepared for the sudden speed up, although her diaper suffered more as the car swerved into the opposite lane of travel, throwing her onto Miyu’s lap. Illya expected more of a reaction from Miyu, but the girl was only shivering and holding her skirt, the darkened patch on it revealing what happened. While she moved to try to console Miyu, a familiar sound resonated to Illya while she found herself rising on Miyu’s lap. There wasn’t any use in checking her own diaper yet as the tighter grip of Miyu’s said everything and the squelching came again from under the dark-haired girl, Illya’s nose getting quite the rough treatment in her position.

And yet before she could try to calm Miyu down, Illya found herself tossed back the other way against the car door, lifting her butt up as another surprise didn’t even have time to threaten her before she found her big butt cheeks parting. Straining felt like it was only delaying the inevitable as she was already peeking out, the mess slowly slipping out more as the car jostled her back and forth until Illya couldn’t hold it anymore. The thickness of her shit at first stretched her anus, the tightness the only thing keeping it in barely at all, but one especially big bump of the car made it rocket out. Her rear crinkled and squished as her diaper swelled from the large mess and another wetting, a warm feeling on Illya’s legs turning out to be Miyu again. It was a momentary relief of not having leaked her diaper yet as Illya’s stomach tied in knots and a second mess poured out of her. She could feel the warm ickiness of the mess mushing against her butt, and the bumps of the car squishing her padded poopy only further helped to make her little peepee tighten against the front of her wet and soiled diaper.

Looking over to her companions though, she wasn’t the one having the most fun in her underwear. Chloe had a big smile on her face, even if Illya could see a couple of beads of sweat. Her butt squishing back and forth in her own seat from Mama’s erratic driving, Illya leaned forward a bit to call out to the girl biting her lip in excitement. “Chloe, are you-uuuugh…” Another jerk of the car and Illya found her seatbelt giving enough leeway to send her tumbling onto Miyu’s lap more than last time, right near Chloe’s waist as Illya lifted her head to the source of some sudden giggling.

Something else lifted as well as Chloe snickered, her seatbelt clicking undone while her butt shifted to being right in front of Illya’s face. “Yeah, I’m okay, but I think Mama’s driving is going to make me have an…” Grunting barely at all, those white panties of Chloe’s turned light brown as Illya tried to escape the sudden reach of the bulging mess. “...Ooooopsie!~” Yet as much as she tried to avoid it, the howl of burning rubber from Iri drifting the car around the last corner to their elementary school sent Illya right back against the light-brown buttcheeks and panties, the warmth smushing against her face as another wave of the mess erupted into the cotton material. Illya could hear the crackling from within the thick mess, more squelching out of the loose loli butt to warm Illya’s face up between that and the heavy blush.

Hitting a light incline though knocked Illya just farther away enough from the stinking panties to give her some barely fresher air, the car speeding up more as she bounced against Miyu’s chest. A squeak came out from the raven-haired girl and Illya thought it was because she hit her after the sudden acceleration, but the lightness that Illya felt alerted her to the fact that they weren’t on the road anymore. Iri proved her amazing driving skills once again as the car caught air, the driver letting out an entertained laugh while another short squeal came from Miyu. The poor girl’s panties sagged lower while she was lifted a little off her seat with her seatbelt limiting her, the poopy panties squashed hard against the seat as the car hit the ground and screeched to a halt, but the sound to the left of both girls even drew Miyu’s attention. 

The brown butt with the brown and bulging panties crashed down against her seat barely a moment after Miyu and Illya both did, splatting her large mess under her big butt as Chloe’s moans echoed in the small car. Not even before her moans were finished did something spurt out of her, surprisingly not out of her ass as Chloe’s petite cock sent a sticky burst onto her skirt, the front of her panties glazed with her cum as the excess oozed and dripped onto the seat. “Hehe, looks like we made it to school. Coming through~” Not even taking the time to recover after her orgasm in her heavily soiled panties, Chloe hurried to move out of the car by sliding onto Miyu’s lap, mushing around on top of it while her victim didn’t even really react. The same treatment happening to her, Illya squirmed under such full underwear, her own cock hardening but Chloe got off of her faster than Illya would have preferred. “Bye, Mama~” With a wave, Chloe hurried towards the school gates, leaving Illya and Miyu in the car.

“Such a naughty girl, I bet she thinks I didn’t notice her seatbelt. I hope she’ll enjoy her punishment after school is over, but keep that between you and me, Illya. Make sure to take care of your friend though, I think she was a little too impressed by my driving~” Her attention consumed before by her twin’s ruined underwear, Illya focused back on Miyu, the poor girl having a thousand-yard stare despite Illya waving her hand in front of her. “Thank you for driving us to school, Mama. I’ll take care of Miyu, and sorry for your seats. Chloe and Miyu…” Glancing down at her own seat as she lifted her butt up to move out of the car, Illya had to add, “and I, uh… you might need Sella to clean up the seats a bit…” Taking Miyu’s hand, Illya led her out of the car and towards the school gates, the pair of girls waddling as Miyu was still unresponsive. The only sound that came from her was the sound of splashing against the cement of the school grounds. “O-oh, Miyu…”

Rolling down the passenger window, Irisviel called out to the pair, “Wait, Illya!~” but she was just a little too out of range for her daughter to hear. Illya was a smart girl though, surely she’d notice and Iri revved the engine again, trying to remember where in the garage she left some of the supplies for when Illya when an even littler girl. 

Tires grinding against the ground sounded off again as Illya waved goodbye to her mother, her heart racing as she felt her hand squeezed. She thought Miyu was turning back to normal, but the small girl was frozen stiff. Illya once more heard the squishing of panties filling up with more crap, and if it wasn’t herself and Chloe had already toddled towards the school building, then… Sighing deeply, Illya wasn’t quite sure how their school day would go with Miyu in this condition and Chloe so excited. With all their friends there too, there was no telling what could, or would, happen.

Illya might have thought Miyu was being her usual stoic self, but her newfound incontinence was speaking for her here instead of her weapon, leading Illya to wonder if she'd have to act as Miyu's mommy for all of the school day. But, considering how her and Mama got along, maybe that wouldn't be so bad…~


End file.
